1. Field of the Invention
The present invention relates to a belt-loop supply apparatus, and more particularly to a belt-loop supply apparatus which is capable of reliably and stably supplying, to a sewing position, a belt loop formed into a predetermined shape.
2. Related Background Art
Belt-loop sewing machines have been suggested each of which is capable of sewing a multiplicity of belt loops, through which a belt is inserted, to the waist portions of a variety of sewn products, such as jeans, pairs of pants and skirts. The belt-loop sewing machine is provided with a belt-loop supply apparatus which is capable of automatically supplying a belt loop to a sewing position of the belt-loop sewing machine.
FIGS. 20 and 21 are diagrams showing an example of a belt-loop supply apparatus provided for a conventional belt-loop sewing machine. An apparatus of the foregoing type has been disclosed in, for example, U.S. Pat. No. 5,673,639. The conventional belt-loop supply apparatus 1 is disposed beside a body 2A of a belt-loop sewing machine 2 which is a sewing means.
The body 2A is, for example, twin-needle cycle machine having a bed 3 disposed in a lower portion thereof. Moreover, an arm 4 paralleling the bed 3 is disposed in an upper portion of the body 2A. Two needles 5 paralleling the lengthwise direction of the arm 4 is disposed at a required position on the lower surface of a free end of the arm 4 which is called a machine head. Each of the needles 5 is joined to a known needle bar 28 (see FIG. 21) which is capable of performing a reciprocating motion for a predetermined vertical stroke by a known needle-bar operation mechanism. The needle-bar operation mechanism is operated in synchronization with the rotation of an upper shaft which is rotated by a machine motor (not shown) rotatively disposed in the arm 4. A known cloth retaining unit (not shown) is disposed at a required position of the arm 4, the cloth retaining unit incorporating two cloth retainers 7 permitted to be moved vertically and structured to retain sewn product S on an upper surface of a needle plate 6 on the upper surface of the bed 3 during a sewing operation.
The belt-loop supply apparatus 1 incorporates a tape supply means 8, a tape bringing/holding means 9, a tape cutting means 10 and a loop supply means 11.
The tape supply means 8 is provided for the purpose of supplying, to a belt-loop forming position adjacent to a sewing position of the body 2A, an elongated tape 12 for forming belt loops. As shown in FIG. 20, a tape delivery frame 13 is disposed on the right side of the body 2A to substantially parallel the bed 3. The tape 12 is placed on the upper surface of the tape delivery frame 13. A delivery roller 14 is disposed above the tape delivery frame 13 so as to deliver the tape 12 for a predetermined length toward the belt-loop forming position. The delivery roller 14 can be brought into contact with the upper surface of the tape 12. The delivery roller 14 can be rotated by a tape delivering motor (not shown).
The tape bringing/holding means 9 brings, to a predetermined position, an end of the tape 12 supplied to the belt-loop forming position, that is, the right-hand end of the tape 12 shown in the right-hand portion of each of FIGS. 20 and 21. Then, the tape bringing/holding means 9 holds the right-hand end of the tape 12 at the predetermined position. The tape bringing/holding means 9 incorporates guide rods 17 for, bringing, to abutting members 16, the tape 12 supplied to the upper surfaces of stationary receiving plates 15. In addition, the tape bringing/holding means 9 incorporates compression coil springs 18 for holding, on the receiving plates 15, the tape 12 brought to the abutting members 16. The guide rods 17 and the compression coil springs 18 can be moved vertically by tape-bringing/holding operation means 19 comprising air cylinders.
The tape cutting means 10 cuts the tape 12 held on the receiving plates 15 by the tape bringing/holding means 9 at the base portion thereof to form a belt loop 20 having a predetermined length. The tape cutting means 10 has a movable blade 21 disposed above a front end of the tape delivery frame 13. The movable blade 21 is, by a tape-cutting operation means comprising an air cylinder (not shown), enabled to perform a reciprocating motion in the vertical direction. In cooperation with a stationary blade 29 (see FIGS. 22 and 23) disposed below the movable blade 21, the movable blade 21 cuts the tape 12.
The loop supply means 11 folds the two ends of the belt loop 20 cut to have the predetermined length toward the central portion of the belt loop 20 so as to bring the two ends to the sewing position of the body 2A below the needle 5. The loop supply means 11 incorporates a pair of bending shafts 22 each of which is called a fork having forked leading ends. The base portions of the bending shafts 22 are, as shown in FIG. 21, connected to bent shaft operation means 23 (see FIG. 21) comprising rotary cylinders which are independently disposed at the lower ends of a seesaw guide lever 25 rotatively supported by a movable bracket 24. The movable bracket 24 is connected to a bent shaft moving means 26 substantially horizontally disposed above the movable bracket 24 and comprising three-stage air cylinder. When the bent shaft moving means 26 is operated, the movable bracket 24 can be moved to and from the sewing position.
The operation of the conventional belt-loop supply apparatus 1 structured as described above will now be described. Initially, the tape 12 is delivered from the tape delivery frame 13 to the belt-loop forming position by dint of rotations of the delivery roller 14. Then, the tape 12 is supported by the receiving plates 15 from lower positions. When the tape 12 has been supplied to the upper surfaces of the receiving plates 15, the tape-bringing/holding operation means 19 are turned on so that the guide rods 17 and the compression coil springs 18 are moved downwards. Then, the tape 12 is, by the guide rods 17, brought to the positions of the abutting members 16. Then, the tape 12 is pressed and held by the compression coil springs 18. Then, as shown in FIG. 22, the bent shaft moving means 26 is operated so that the bending shafts 22 are, together with the movable bracket 24, forwards moved toward the tape 12 positioned at the belt-loop forming position. Then, the forked leading ends of the bending shafts 22 are inserted into portions adjacent to the two ends of the tape 12 removed from the receiving plates 15.
Then, as shown in FIG. 23, the tape-cutting operation means (not shown) is operated so that the movable blade 21 is moved downwards. Thus, the movable blade 21 cuts the base portion of the tape 12 in cooperation with the stationary blade 29. Thus, a belt loop 20 having a predetermined length is formed. Then, the bent shaft operation means 23 are operated so that the bending shafts 22 are rotated outwardly as indicated by an arrow A shown in FIG. 23. As a result, the two ends of the belt loop 20 are downwards folded toward the central portion of the belt loop 20. That is, the belt loop 20 is folded by about 180.degree.. At this time, either side surface of the tape 12 has been brought into contact with the abutting members 16 and positioned at a predetermined position by the tape bringing/holding means 9. Therefore, when the two ends of the belt loop 20 cut to have the predetermined length are folded by the bending shafts 22, devastation of the bent portions can be prevented. That is, the two ends can completely be laid to overlap each other.
Then, as shown in FIG. 24, the tape-bringing/holding operation means 19 are operated so that the guide rods 17 and the compression coil springs 18 are moved upward. Thus, the state in which the belt loop 20 is held by the receiving plates 15 and the compression coil springs 18 is suspended.
Then, the bent shaft moving means 26 is operated so that the bending shafts 22 are, together with the movable bracket 24, forwards moved to positions on this side of the sewing position, as shown in FIG. 21. Specifically, the bending shafts 22 and the movable bracket 24 are moved to positions above the side end of the needle plate 6 of the belt-loop sewing machine 2. Thus, the belt loop 20 having the two folded ends is made to be on standby.
Then, an operator positions the sewn product S at a predetermined position on the needle plate 6, and then the operator switches on a loop supply switch 27 (see FIG. 21). Thus, the bent shaft moving means 26 is operated so that the movable bracket 24 are, together with the movable bracket 24, forwards moved toward the sewing position. As a result, the belt loop 20 having the two folded ends is brought to the sewing position. Specifically, the belt loop 20 is moved to a position below the cloth retainers 7.
Then, the cloth retainers 7 are moved downwards to hold the two folded portions of the belt loop 20. Then, the bent shaft moving means 26 is operated so that the bending shafts 22 are moved rearwards together with the movable bracket 24. Then, the leading ends of the forked bending shafts 22 are removed from the two folded portions of the belt loop 20. Then, for example, the two side portions of the belt loop 20 in the lengthwise direction of the belt loop 20 are sewn in accordance with a predetermined sewing pattern. Thus, the belt loop 20 can be sewn to a predetermined position of the sewn product S.
After the bending shafts 22 have been moved rearwards, the bent shaft operation means 23 are operated. Thus, the bending shafts 22 are reversely rotated so that the bending shafts 22 are restored to the initial positions. Then, a similar operation is performed so that a belt loop 20 for use in a next sewing operation is formed. The formed belt loop 20 is made to be on standby at a position on this side of the sewing position.
At the present time, high-quality products sewn satisfactorily are required. To improve the quality of the belt loop 20 which is sewn to the waist portion of the sewn product S by the belt-loop sewing machine, a belt-loop supply apparatus which is capable of reliably and stably supplying the belt loop 20 to the sewing position has been required.
That is, a belt-loop supply apparatus which is capable of reliably and stably supplying the belt loop 20 having a predetermined shape to the sewing position has been required.